From Longman Dictionary of Contemporary Englishplummyplum‧my /ˈplʌmi/ adjective 1 SPEAK A LANGUAGE British English informal a plummy voice sounds very upper-class2 CTlike a plum in taste, colour etc a plummy wine
Examples from the Corpus
plummy• It has some plummy fruit, with sufficient tannin for only £2.74.• It goes well with Cabernet, offsetting that grape's fruitiness with its plummy taste.• In spite of that plummy voice, she'd make it all right, or his name wasn't Walter Wetherby! 